BOSTON — Third-grader Martin Richard had just gotten ice cream and was near the Boston Marathon finish line, eagerly watching for friends to run by. Krystle Campbell was enjoying the race with her best friend, hoping to get a photo of the other woman's boyfriend after he conquered the last mile.

Then the unthinkable struck. The spirited 8-year-old with a wide grin who dressed up one Halloween as Woody from "Toy Story" was dead, along with the outgoing 29-year-old woman and a Boston University graduate student from China— victims of twin blasts that turned a scene of celebration into chaos.